Molecular identification and phylogenetic analysis of different races of Fusarium oxysporum f.sp. Melonis in muskmelon using RAPD markers under Punjab conditions

Abstract

Muskmelon wilt caused by Fusarium oxysporum f.sp. melonis causes serious damage in muskmelon growing districts of Punjab. Keeping in view the importance of disease, the present study was conducted with an objective to identify the different races of muskmelon wilt using molecular techniques. Twenty isolates of F. oxysporum f.sp. melonis were collected in 2018 and 2019 from different locations of muskmelon growing areas of Punjab viz. Jalandhar (J) Kapurthala (K), Sangrur (S) and Patiala (P). Pathogenicity for the evaluation of prevalent races of F. oxysporum f.sp. melonis under Punjab conditions was performed on a set of five differentials viz. Charentais T, Charentais FOM-1, Charentais FOM-2, Margot and Isabelle under pot house conditions. After 2–3 true leaf stage, these differentials were artificially inoculated with spore suspension @ 1x106/ml of twenty isolates of F. oxysporum f.sp. melonis. Findings indicated that out of total 20 isolates, 8 isolates belonged to race 1, 8 isolates belonged to race 1.2, 3 isolates belonged to race 2 and remaining 1 belonged to race 0. Therefore, race 1 and 1.2 were prevalent in Punjab. Genetic diversity among the twenty isolates of F. oxysporum f.sp. melonis was analyzed with the Random Amplified Polymorphic DNA (RAPD) markers. Based on cluster analysis, J2 and J4 isolates were outliers and they were genetically different from other isolates. It was concluded that Fusarium wilt of muskmelon caused by FOM was prevalent in all muskmelon growing districts of Punjab. These findings are considerably important and could be used for selection and integration of muskmelon wilt resistance gene into muskmelon breeding programmes for Fusarium wilt management under Punjab conditions.